I have traced one capacitance multiplier for each channel. A 30+30 transformer yields 38VDC according to Rod's construction article. I'm going to use a 25+25 tranformer because it's what I have on hand so I estimate I will end up in the lower 30s.

I drew one side and saw that I could fit another supply on the board by rotating it 180 degrees. This seemed like a good solution because this board would fit with its long side near the back panel of the enclosure, with the transformer.